1. Field of the Invention
The present invention relates to a storage system, a management server, and a method of managing an application thereof.
2. Description of the Related Art
A host uses a plurality of disk array devices as external storage devices upon operation of an application. A disk array device includes a plurality of disks. To be more precise, the host is connected to the disk array devices through a storage area network (SAN), whereby data are distributed to a logical volume (LU) composed of the plurality of disks to be stored.
As a technology for enhancing fault tolerance of such a disk array device, for example, Japanese Patent Application Laid-open Publication No. 2000-305720 discloses a technology for predicting a failure of a disk. Meanwhile, according to Japanese Patent Application Laid-open Publication No. 2001-167035, a client on a network is monitored by using a WWW browser in order to enhance fault tolerance of the disk array device. Moreover, Japanese Patent Application Laid-open Publication No. Hei11-24850 discloses a technology for recovering data contained in a failed drive such that the data belonging to a volume of a highest frequency of failures first, then the recovery is attempted according to the failure frequency Furthermore, Japanese Patent Application Laid-open Publication No. 2000-20245 discloses a technology for automatically configuring a disk drive connected to a controller.
In general, a disk array device utilizes a “Redundant Array of Inexpensive Disks” (RAID) technology to prevent data loss or system down of a host. Parity and error correction data are added to data to be written, and the data are distributed to a plurality of disks for storage. In this way, it is possible to restore correct data using the parity even if one of the disks is out of order.
However, execution of data restoring processing, when a disk is out of order, incurs performance degradation of operation of an application as compared to a normal condition. Moreover, if a spare disk exists when the drive is blocked, the blocked disk will be restored by using the spare disk. Execution of such restoring processing also incurs performance degradation of an application as compared to a normal condition.
Nevertheless, such restoring processing has been executed without notifying a user. Accordingly, the user would not recognize that the cause of the performance degradation of the application is due to the data restoring processing and has occasionally sought other causes.
In addition, when the drive is blocked, a system administrator receiving such warning has had difficulty predicting influence to the performance degradation of the application.